Based on the ones I have lived through my favourite would be Harry Truman. His administration is the only one in our long history that addressed the problems of returning veterans in a practical way, with proper oversight of the Veteran's Administration (Truman brought Omar Bradley in to make it run) and with the GI Bill, providing education and skills training that helped the vets fit in, improve their lot and build the grat society of the 1950s and 60s. Truman never gets the respect he deserves.

The least is in office right now. Donald Trump accurately represents everything that is shameful and petty about modern America, demonstrating that the children of those 50s and 60s are unworthy of their parents' sacrifices.

Favorite for what he did would be Lincoln. Favorite to read and learn about would be LBJ.
Least favorite - our current one for what he is doing and what he represents. Least favorite to read about - hard to pick.